Core Java Interview Questions, Answers for Freshers and Experienced asked in various Company Job Interviews

Core Java Interview Questions

Questions Answers Views Company eMail

my method "abc" return array of interface "xyz" and "pqr" is abstract class implements abc and class "jkl" extends pqr My problem 1) when i call abc it retrun array xyz how can i do this hint xyz refer_xyz = new jkl(); but i can't create array. 2)I want to access method of jkl using reference of xyz??

1 4001

why interaction with server using javascript is difficult

1 3942

StringBuilder s = new StringBuilder("Hello Mom");s.append(",I mean,Mother"); Response.Write(s.ToString()); String s = "Hello Mom"; s+ = ",I mean Mom"; Response.Write(s); Which is faster ? which uses the most memory?

HCL,

6 9144

I have one Shopping cart application, i that i have selected some items, while clicking submit button by mistake i have clicked twice or trice, that time items are selected twice or trice. Actually i want only one copy of items but its selected twice or trice. So how can we avoid this problem?

Honeywell,

2 6934

How Vector class is synchronized,How to build user defined class as synchronized?

2102

What is difference between abstract class & final class

7 27279

Hai all I want to print given array in reverse order Ex: int a[]={1,2,3,4,5};display this array in reverse order.

4 6231

what is the output ? Math.floor(-2.1) a)2 b)-2 c)-3.0 d)0

Accenture,

4 14027

How to find the size of an array a)array.length() b)array.length c)array.size() d)array.size

Accenture,

6 11143

what is the Yield() method used in threads?

Accenture,

4 8741

System.out.println(101/14) what is the output? a)6 b)14 c)7.14 d)0

Accenture,

8 10896

when a servlet sends request for first time it uses the follwing methods a)init b)doget() c)dopost() d)service

Accenture,

4 7663

What is Hash Code in Java?

Cognizant,

6 16207

What are uses of Hash Code?

Cognizant,

2 7582

I have 100 records in a table with two rows. I need to display 10 records per page like Google Search. I need only the Logic(Pagination) in Pure Java. No JSP and all..Thanks in Advance...

Cybernet,

2 8096

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Un-Answered Questions { Core Java }

What is private public protected in java?

1076

Suppose if we have variable ' I ' in run method, if I can create one or more thread each thread will occupy a separate copy or same variable will be shared?

1126

Name some classes present in java.util.regex package.

1080

What are the 4 types of characters?

1063

why would you use a synchronized block vs. Synchronized method? : Java thread

1000

What is identifier with example?

1096

What is thread start?

1018

why java does not support unsigned keyword?

5344

What is the similarity between dynamic binding and linking?

1171

What is array sorting in java?

1112

how to deploy apache tomcat server to weblogic server in java

2155

How do you use compareto?

991

Is treeset sorted in java?

1042

What is nextline method in java?

1093

What is a platform?

1161

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